Needle shield assembly having a single-use cannula lock

ABSTRACT

A needle shield assembly having a single-use cannula lock of the present invention includes a needle cannula having a proximal end, a distal end and a lumen therethrough. A hub includes a proximal end for connection to a fluid transfer device and a distal end connected to the proximal end of the needle cannula. A collar is rotationally connected to the hub so that the collar can be rotated around the hub. An elongate needle cover removably engages the hub and covers the needle cannula. An elongate needle shield having a proximal end and a distal end is hingedly connected, through its proximal end, to the collar. The needle shield includes two sidewalls defining a longitudinal opening and a back wall between said side walls defining a recess having an interior surface. The needle shield is capable of pivoting from an open position wherein the needle cannula is exposed, to a closed needle protecting position wherein at least part of the needle cannula is within the longitudinal opening of the needle shield. The needle shield assembly further includes structure for preventing the needle shield from pivoting into the closed position unless the needle cover is removed, and structure for locking the needle shield in the closed needle protecting position when the needle shield is pivoted into the closed position. The structure for locking traps the needle cannula in the longitudinal opening of the needle shield.

FIELD OF THE INVENTION

The subject invention relates to needle shields for hypodermic needles,to help prevent accidental contact with the needle.

BACKGROUND

Accidental needle sticks with a used hypodermic needle can transmitdisease. Most prior art needle assemblies have a needle shield. Someneedle shields define a rigid sleeve that can be telescoped distallyover the needle cannula. This procedure requires a healthcare worker tohold the needle assembly or the associated medical implement in one handand the shield in the other. Some medical procedures require theapplication of pressure to the penetration site after the needle hasbeen removed. Thus, healthcare workers are often unable to use bothhands for shielding the needle cannula. In these situations, workersmerely deposit the used medical implement on a nearby surface with theintention of disposing or shielding at a more convenient time. However,until the needle is shielded or properly disposed, the device presents apotential danger to other people.

A needle shield which is hinged near the base of the needle has theadvantage of allowing one-handed needle reshielding, thus providing theopportunity for reshielding, under most circumstances, immediately afteruse.

A hinged needle shield which permanently locks when it is pivoted to theclosed needle shielding position has certain advantages. Primarily,there is no doubt about the status of the needle shield assembly and thehealthcare worker knows that the needle should be carefully disposed ofand not used for further fluid transfer. This is analogous to the priorart rigid cylindrical needle shield which is telescoped over the needlecannula and frictionally engages the needle hub. It is clear with theprior art needle assembly whether the needle is shielded or notshielded. However, having a permanently lockable hinged needle shieldpresents a problem in situations where the needle is intended to be usedtwice. For example, the needle is first used to penetrate the pierceablestopper of a medication vial for the purpose of filing the syringe withmedication for subsequent injection into a patient. The needle shieldassembly with attached syringe is then transported to the patient areafor injection of the medication. If the needle is re-shieldedpermanently after the syringe is filled it cannot be used for injectionand a second needle must be installed at the time of use.

It is advantageous to have a self-.contained needle shield assemblywherein the adapter for the medical implement, the needle cannula, andthe needle shield are all connected in one unit. The prior art includessyringes having cylindrical sleeves over their outside diameter. Afterinjection, the sleeve is advanced to a locked needle protectingposition. The syringes are important safety devices, however, not allsyringes are used with a needle. The use of a self-contained needleshield assembly allows the end user to attach the needle assembly onto avariety of syringe sizes and to inventory standard syringes for alluses. Accordingly, a more costly safety syringe would not have to beused for applications where the safety features are not necessary.

It is also advantageous to have an enclosed needle cover that protectsthe cleanliness of the needle even after the needle shield assembly isremoved from its sterile package. An enclosed needle cover protects allsides of the needle while a hinged needle shield has one open side andallows exposure of the needle to airborne particles.

Although the prior art provides many improved needle shield devices,there is still a need for a self-contained needle shield assemblywherein the needle shield can be positioned in the needle shieldingposition using a one-handed procedure and the needle shieldautomatically locks in the needle shielding position and is unable to bereused. There is a need for a self-contained needle shield assemblywhich allows the needle to be used twice, once for withdrawingmedication into a Syringe and then for injecting the medication into apatient wherein the needle may be shielded between the first and seconduse. There is a need for a needle shield assembly which protects thecleanliness of the needle after the needle shield assembly is removedfrom its sterile package. There is also a need for a needle shieldassembly that provides the shortest possible fluid path between thesyringe barrel and the needle tip to avoid loss of medication in thefluid path which cannot be expelled.

SUMMARY OF THE INVENTION

A needle shield assembly having a single-use cannula lock of the presentinvention includes a needle cannula having a proximal end, a distal endand a lumen therethrough. A hub includes a proximal end for connectionto a fluid transfer device and a distal end connected to the proximalend of the needle cannula. A collar is rotationally connected to the hubso that the collar can be rotated around the hub. An elongate needlecover removably engages the hub and covers the needle cannula. Anelongate needle shield having a proximal end and a distal end ishingedly connected, through its proximal end, to the collar. The needleshield includes two sidewalls defining a longitudinal opening and a backwall between said side walls defining a recess having an interiorsurface. The needle shield is capable of pivoting from an open positionwherein the needle cannula is exposed, to a closed needle protectingposition wherein the needle cannula is within the longitudinal openingof the needle shield. The needle shield assembly further includesstructure for preventing the needle shield from pivoting into the closedposition unless the needle cover is removed, and structure for lockingthe needle shield in the closed needle protecting position when theneedle shield is pivoted into the closed position. The structure forlocking traps the needle cannula in the longitudinal opening of theneedle shield.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of the needle shield assembly of thepresent invention attached to a syringe before being used.

FIG. 2 is an exploded view illustrating the needle shield assembly ofthe present invention attached to a syringe with the needle cover andportions of the hub illustrated in cross-section.

FIG. 3 is a top plan view of a needle shield and collar assembly for usein the present invention.

FIG. 4 is a cross-sectional view of the needle shield and collarassembly of FIG. 3 taken along lines 4--4.

FIG. 5 is a cross-sectional view of the needle shield and collarassembly of FIG. 3 taken along lines 5--5.

FIG. 6 is a cross-sectional view of the needle shield and collarassembly of FIG. 3 taken along lines 6--6.

FIG. 7 is a side elevation view of the needle shield assembly of thepresent invention attached to a syringe at the time of first use.

FIG. 8 is a side elevation view of the needle shield assembly of thepresent invention after use with the needle shield in the closedposition.

FIG. 9 is a perspective view of an alternative needle shield assembly ofthe present invention attached to a syringe.

FIG. 10 is a cross-sectional view of an alternative needle shield.

FIG. 11 is a side elevation view of an alternative needle shieldassembly of the present invention illustrated without the collar andneedle shield.

FIG. 12 is another alternative embodiment of the present needle shieldassembly.

FIG. 13 illustrates an alternative needle shield and collar assembly.

DETAILED DESCRIPTION

While this invention is satisfied by embodiments in many differentforms, there are shown in the drawings and will be herein described indetail preferred embodiments of the invention with the understandingthat the present disclosure is to be considered exemplary of theprinciples of the invention and not intended to limit the scope of theinvention to those embodiments illustrated. The scope of the inventionwill be measured by the appended claims and their equivalents.

Adverting to FIGS. 1-8, a needle shield assembly having a single-usecannula lock, such as needle shield assembly 20, includes a needlecannula 21 having a proximal end 22, a distal end 23 and a lumentherethrough defining a longitudinal axis 25. In this preferredembodiment, the distal end of the needle cannula includes sharpened tip26. It is within the purview of the present invention to include bluntcannula which are cannula without sharp tips. Blunt cannula are known inthe an and are usually used to inject liquid into an I.V. set or otherfluid path having an access port with a pre-slit septum. The bluntcannula is forced through the slit in the septum and into fluidcommunication with the fluid flow path. Upon removal of the bluntcannula, the slit portion of the septum automatically seals itself.

A hub 28 includes a proximal end 29 and a distal end 31 connected toproximal end 22 of the needle cannula. The hub includes a base member 30which for the purposes of describing the instant invention is part ofthe hub. There are many ways of connecting the base member to the hub,such as through interference fit, adhesives, ultrasonic welding and thelike. It is within the purview of the present invention to include a huband its base member which are of a unitary one-piece structure. Theone-piece structure may be accomplished by many methods includinginjection molding the hub and base member as a one-piece unit therebyeliminating the need to assemble the base member to the hub during themanufacturing process. In this preferred embodiment, the collar isrotatably connected to the hub in a snap-fit arrangement which allowsthe collar, through application of manual force, to be rotated aroundthe hub. The rotational connection of the collar and hub is accomplishedby interaction between structure on the hub including proximal raisedportion 32, distal raised portion 33 and collar receiving recess 34 andthe collar. The distance across proximal raised portion 32 and distalraised portion 33 is greater than the inside diameter of collar 41 andgreater than the diameter or distance across recess 34. During assembly,the collar is passed over the distal end of the hub and forced overdistal raised portion 33 so that it snaps into the space between raisedportion 32 and raised portion 33 and is trapped in that position. It ispreferred that there be a certain amount of frictional engagementbetween the collar and the hub so that the collar cannot rotate toofreely with respect to the hub. As will be explained in more detailhereinafter it is desirable to be able to rotate the needle shield withrespect to the needle hub and have the shield maintain itself in theselected position. This can be accomplished in many ways, such as, bymaking the distance between raised portion 32 and raised portion 33 lessthan the thickness of collar 41 and/or making the diameter or distanceacross recess 34 slightly larger than the inside diameter of the collarto provide a frictional relationship between the collar and the hub.Also mechanical retention can be provided by placing a series ofprojections on the hub or inside the collar and a series of recessesinside the collar or on the hub. The projections can engage the recessesto position the collar with respect to the hub but still allow rotationby overcoming the force of the projection and recess engagement.Interior surface 43 of collar 41 can be formed in a variety of shapessuch as a constant inside diameter. In this preferred embodiment,interior surface 43 is defined by four segments along minor diameter Cand four segments along major diameter D, as best illustrated in FIG. 3.Minor diameter C is slightly smaller than the diameter of recess 34 onhub 28. This stepped configuration makes the collar less sensitive tomanufacturing tolerances so that the frictional fit between the collarand the hub can be more tightly controlled. The stepped configurationalso gives the collar some flexibility to allow it to be easily snappedinto place during the assembly process. The advantages of rotationallyconnecting the collar to the hub will be explained in more detailhereinafter.

An elongate rigid needle cover 37 having a cylindrically-shaped sidewall 38 and an open proximal end 39 removably engages hub 28 and coversneedle cannula 21, as best illustrated in FIG. 2. A needle cover is animportant advantage of the present invention. Preferably, the needleassembly is manufactured and sterilized in a protective package with theneedle cover in place. The needle cover provides a contamination barrierfor the needle after the needle shield assembly is removed from thesterile package. Accordingly, the user is assured of a clean needle atthe time of first use. At the time of first use, the needle cover isremoved, as illustrated in FIG. 7, by overcoming engagement forcesbetween the needle hub and the open proximal end of the needle cover.

An elongate needle shield 45 having a distal end 46 and a proximal end47 is hingedly connected to collar 41. In this preferred embodiment,needle shield 45 is hingedly connected to collar 41 through living hinge44. It is within the purview of the present invention to include anystructure for hingedly connecting the shield to the collar so that theneedle shield may be pivoted with respect to the collar. Thesestructures include known mechanical hinges and various linkages, orcombinations of hinges and linkages. Needle shield 45 includes two sidewalls 50 and 51 defining a longitudinal opening 52 and a back wall 53between the side walls defining a recess 55 having an interior surface56

The needle shield assembly of the present invention is suitable for usewith fluid delivery devices such as syringes. For the purpose ofillustration, needle shield assembly 20 is illustrated connected tohypodermic syringe 70 comprising a syringe barrel 71 having a distal end73, a proximal end 74 and a circular side wall 75 defining a chamber 76for retaining fluid and a longitudinal axis 80. Volume measuring indicia72 are on the barrel for measuring the dose of medication to bedelivered. The distal end of the syringe barrel is connected to the hubso that the lumen of the needle cannula is in fluid communication withchamber 76 of the syringe barrel. In this embodiment, distal end 73 ofthe syringe barrel includes a frusto-conically shaped tip 77 having apassageway therethrough which provides a fluid path between the cannulaand the chamber. The frusto-conically shaped tip of the syringe barrelfrictionally engages a frusto-conically shaped cavity in the needle hub.The distal end of the syringe barrel also includes a locking luer-typecollar 79 concentrically surrounding the tip. The luer collar has aninternal thread which engages the needle hub to hold it securely to thebarrel. It is within the scope of the present invention to includevarious hub configurations to attach to a wide variety of medical orother fluid handling devices. The hub configuration describedhereinabove, having a frusto-conically shaped interior cavity, reflectsone of these many possibilities. Many syringes, fluid handling devices,such as stopcocks and adapters, and other fluid handling devices containluer slip and locking luer-type fittings to which the hub of afrusto-conically shaped interior cavity will properly engage. It is alsowithin the purview of the present invention to provide a needle shieldassembly wherein the hub is integrally molded with the syringe barrel.

It is an important feature of the present invention that all elements ofthe needle shield assembly are connected to the hub and that the hub iscapable of directly connecting to a fluid handling device such as asyringe. Some prior art devices contain a separate housing which mountsbetween the needle hub and the syringe, wherein the needle shield ishingedly connected to the separate housing. A separate housing lengthensthe fluid flow path between the chamber in the syringe and the distalend of the needle cannula thereby wasting medication, because it cannotbe expelled, the fluid flow path through the housing must be filled withmedication before medication can leave the proximal end of the needle.In some cases, the medication may cost one hundred times more than thesyringe and small amounts of medication lost over a substantial numberof syringes can result in a substantial unnecessary loss of valuablemedication. Also, the additional element increases the length betweenthe syringe and the needle tip possibly making it slightly moredifficult to accurately position the needle, for example in a patient'svein.

The use of a needle cover and a hinged needle shield in the needleshield assembly of the present invention provides other advantages inthe manufacturing and assembling of the needle shield assembly. Mostnotably, the needle cannula, hub and needle cover can be manufactured asa separate assembly. So long as the needle cover is attached to the hubthe needle cannula and in particular the sharpened tip of the needlecannula is protected from damage and contamination. The final assemblystep involves slipping collar 41 over needle cover 37 until the collarsnaps into place on the collar receiving recess 34 of the hub. Tofacilitate this assembly, needle cover 37 includes annular flange 40which has a tapered outside surface to allow the collar to pass smoothlyover annular flange 40 and distal raised portion 33 of the hub and intorecess 34 during assembly. Further, this final assembly step isaccomplished while the fragile needle cannula is protected by needlecover 37, thus avoiding contamination and damage to the needle cannula.

Needle shield 45 is capable of pivoting from an open position whereinneedle cannula 21 is exposed, as best illustrated in FIG. 7, to a closedneedle protecting position wherein at least part of needle cannula iswithin the longitudinal opening of the needle shield, as bestillustrated in FIG. 8.

As will be explained in more detail hereinafter, an important feature ofthe present invention includes means for preventing the needle shieldfrom being pivoted into the closed position before the needle cover isremoved. In this preferred embodiment means for preventing isaccomplished forming at least a portion of the side walls so that thelongitudinal opening is smaller than the needle cover, so that theneedle cover must be removed before the needle shield can be pivotedinto the closed needle protecting position. It is within the scope ofthe present invention to include many structures which prevent themovement of the needle shield into the closed needle protecting positionbefore the needle cover is removed. Such structures may include aprojection on the needle shield, the needle cover or on both elementswhich creates an interference between the needle shield and the needlecover which prevents moving the needle shield into the closed needleprotecting position.

Another important feature of the present invention includes means forautomatically locking the needle shield in the closed needle protectingposition when the needle shield is pivoted into the closed position."Automatically" is intended to mean that movement of the needle shieldsufficiently into the needle protecting position will cause locking tooccur automatically without further action on behalf of the user."Permanently" is intended to mean that there is no unlocking structure,and the needle will remain shielded until proper disposal. The lockshould generally withstand the normal forces encountered during properdisposal of the needle shield assembly. Excessive forces applied to theneedle shield will bend the needle cannula but not allow the needlecannula to be re-exposed.

In this preferred embodiment, means for locking the needle shield in theclosed needle protecting position includes needle cannula locking meansfor trapping the needle cannula in the longitudinal opening of theneedle shield. In this preferred embodiment needle cannula locking meansincludes an arm 58 projecting from interior surface 56 of the needleshield. Arm 58 includes a transverse portion 61 at its free end 59.Transverse portion 61 includes a ledge 62 which is positioned so thatwhen the needle shield is pivoted to the closed position, needle cannula21 snaps past transverse portion 61 and is trapped in the needle shieldby ledge 62. The action of the needle cannula snapping past thetransverse portion can be accomplished by deflection of the arm and/orthe transverse portion, by deflection of the needle cannula or by acombination of all elements so that after the needle cannula passes thetransverse portion, the parts return generally to their undeflectedposition or at least to a position where the needle cannula cannotreverse its path and remains trapped in the recess of the needle shield.The retention forces are preferably such that an attempt to return theneedle shield to the open needle exposing position will cause the needleto be bent in that direction but usually not re-exposed. In thispreferred embodiment arm 58 extends from interior surface 56, and inparticular outwardly from back wall 53. However, the arm could alsoextend from either of the side walls and still achieve a similar result.

In this preferred embodiment needle cannula locking means also includesfirst inclined wall 64 and second inclined wall 65 having exteriorsurfaces 67 and 68 respectively for urging the needle cannula toward thecenter of longitudinal opening 52 as the needle shield is being rotatedinto the closed position. The inclined walls are especially helpful ifthe longitudinal axis of the needle cannula is misaligned with respectto the longitudinal axis of the hub and syringe. The exterior surfaceswill urge the needle cannula toward a central position so that itproperly engages and is trapped by the arm structure. Although theinclined walls are not necessary for the present invention at least onewall is desirable and two walls, as best illustrated in FIGS. 3 and 5,are preferred.

Referring to FIGS. 7 and 8 it can be seen that the needle shield can bemoved from the open position to the closed position using asingle-handed procedure. For example ,by grasping syringe 70 with thefingers and advancing the needle shield from the open to the closedposition by pressing on the back wall with the thumb until the needleshield is in the closed locked position. To facilitate the single-handedoperation of the needle shield, finger pad 69 is provided at theproximal end of the needle shield.

It is desirable to have means for releasably retaining the needle shieldin the open position. Holding the needle shield in the open positionkeeps it from interfering with the injection process either visually orphysically. Releasably retaining the needle shield in the open positionmay be accomplished by dimensioning parts of the assembly so thatfriction is created in the hinge or by using an articulated over-centerhinge or by creating some interference between the needle shield and thecollar which must be forcefully overcome to move the needle shield outof the open position. In this embodiment, as best illustrated in FIG. 4,projection 82 on the collar will engage edge 85 of aperture 83 when theneedle shield is pivoted to the open position. Additional force isrequired to pivot the needle shield out of the open position. In theopen position, it is preferred that longitudinal opening 52 be orientedfrom between about 90° to 180° from longitudinal axis 25 of the needlecannula, as best illustrated in FIG. 7, where the needle shield isrotated so that longitudinal opening 52 is about 150° from longitudinalaxis 25 of the needle cannula.

As best illustrated in FIG. 7., sharpened tip 26 of needle cannula 21 issharpened to a bevel shape having a bevel surface 27 oriented at angle Awith respect to longitudinal axis 25. Bevel surface 27 faces directionB. The rotational connection of the collar to the hub is an importantfeature of the present invention because it allows rotation of theneedle shield so that the bevel surface faces the same side of thecollar as the needle shield when the needle shield is in the openposition. Rotation of the needle shield to this position optimallyorients the bevel surface and makes it easier to insert the needle intoa patient's vein or subcutaneously. Also, it is desirable to have bevelsurface 27 facing the same side of the needle assembly as the needleshield when the needle shield is in the open position, so that theneedle shield does not interfere with positioning the syringe at a lowangle close to the patient's body, for example, the patient's arm, whenattempting to gain access into a vein. In addition, the ability torotate the needle shield with respect to the hub allows the needleshield to be positioned to avoid blocking the user's view of volumemeasuring indicia on the syringe barrel.

FIG. 1 illustrates needle shield assembly 20 connected to hypodermicsyringe 70 in a configuration in which it is likely to be delivered, insterile form, from a manufacturer. Placing needle shield 45 in anintermediate position between the closed position and the open position,closer to the closed position, creates a configuration which takes upless packaging and shipping carton space. This is especially true whenthe needle shield assembly is being shipped separately without beingattached to a fluid delivery instrument such as a syringe. Also, in thisintermediate position, the needle shield assembly is easier to handlefor the purposes of installing it onto a fluid delivery device, such asscrewing the hub onto a standard locking luer-type fitting. Accordingly,it is desirable to provide means for releasably retaining the needleshield in an intermediate position between the open position and theclosed position. In this preferred embodiment means for releasablyretaining the needle shield in the intermediate position includesprotrusions 86 and 87 projecting inwardly from side walls 50 and 51respectively engage the outer surface of needle cover 37 to bias theneedle shield toward the needle cover. An additional force is requiredto pivotably move the needle shield from the intermediate position tothe open position.

FIG. 9 illustrates an alternative needle shield assembly of the presentinvention. The alternative needle shield assembly functions similarly tothe needle shield assembly of FIGS. 1-8. Alternative needle shieldassembly 90 includes collar 141 and a needle shield 145 hingedlyconnected to the collar through hinge 144. Means for releasablyretaining the needle shield in the open position includes a projection91 on the collar and finger pads 92 and 93, on the needle shield,defining slot 94 therebetween. The width of slot 94 between finger pads92 and 93 is preferably equal to or slightly less than the width ofprojection 91 on the collar so that when the needle shield is pivoted tothe open position projection 91 enters slot 94 and is frictionallyengaged therein by the sides of finger pads 92 and 93. Projections orrecesses can be provided alternatively on projection 91 and in slot 94to provide for a mechanical engagement of the needle shield to thecollar when the needle shield is in the open position. In any case, theneedle shield is releasably retained in this position and additionalforce will be needed to overcome the frictional or mechanical engagementof the projection to the needle shield to advance the needle shield tothe closed position. Discontinuous surfaces 95 and 97 are provided tohelp to provide a more positive connection between the user's finger andthe needle shield when advancing the needle shield to the closedposition.

FIG. 10 illustrates an alternative needle shield for use with the needleshield assembly of the present invention. The alternative needle shieldof the embodiment of FIG. 10 functions similarly to the needle shieldassembly of FIGS. 1-8.

Alternative needle shield 100 includes side walls 150 and 151 defining alongitudinal opening 152 and a back wall between the side walls defininga recess 155 having an interior surface 156. Needle cannula lockingmeans for trapping the needle cannula in the longitudinal opening of theneedle shield includes an arm 158 having a transverse portion 161 at itsfree end including a ledge 162 positioned so that when the needle shieldis pivoted to the closed position, the needle cannula 121 snaps pasttransverse portion 161 and is trapped in the needle shield by a ledge162.

FIG. 11 illustrates an alternative needle shield assembly 200 of thepresent invention illustrated without the collar and needle shield. Inthis alternative embodiment a base member 230 is integrally molded andis part of a hub 228. Hub 228 further includes an enlarged portion 235to facilitate removal and installation of the needle assembly. Becausethe collar is rotatably connected to the hub it may be difficult toinstall and remove the hub from a hypodermic syringe because rotation ofthe assembly will cause the shield and its connected collar to rotatearound hub 228. The enlarged surface 235 provides a surface to grab tofacilitate the removal and installation of the needle shield assembly.In this embodiment, enlarged portion 235 has an octagonal shape tofurther increase its utility as a gripping surface. In addition, hub 228includes radially outwardly projecting tab 236 which further acts as anenhanced point of contact for connecting and disconnecting the needleshield assembly from a hypodermic syringe or similar device. Ways tofacilitate the installation of the needle shield assembly of the presentinvention include providing structure on the hub which engages therotatable shield when it is in the closed or intermediate position.Also, ribs can be provided on needle cover 37 to facilitate rotation ofthe cover which in turn rotates the hub. Also, side walls 50 and 51 ofthe needle shield can be designed to be flexible enough so that handapplied squeezing forces applied to the needle shield while it is in itsintermediate position will cause the shield side walls to collapse andgrab needle cover 37 so that torque may be transmitted the needleshield, through the needle cover to the hub. Likewise, the needle shieldsidewalls can be designed to grab the hub when the needle shield is inthe closed position. Accordingly, the present invention provides meansfor applying torque to the hub to facilitate installation and removal ofa needle shield assembly from a hypodermic syringe or similar device.Means for applying torque include alternative accessible hub structuresincluding those with enlarged portions, such as enlarged portion 235and/or radially projecting tabs, such as radially projecting tab 236.Means for applying torque can also include structure for engaging theneedle cover and the needle shield, when the needle cover is in theintermediate position and providing flexible side walls on the needleshield so that digital force will deflect the side walls causing theneedle shield to grab the needle cover for transmitting torque throughthe cover to the hub. Means for applying torque can also includestructure for engaging the needle shield and the hub, when the needleshield is in the closed position, by providing flexible sidewalls on theneedle shield so that digital force will deflect the sidewalls causingthe needle shield to grab the hub for transmitting torque through thehub. Also, the structure for engaging the needle shield and the hub maybe sufficiently strong that, in certain configurations, a flexiblesidewall will not be necessary to apply torque from the needle shield tothe needle hub. Structure on the needle shield for engaging the hub mayinclude a series of inwardly projecting ledges, preferably havingserrated or otherwise roughened distal ends, for contacting the hub andthe plane sufficient frictional force so that rotational force appliedto the shield is transferred efficiently to the hub.

Hub 228 includes proximal raised portion 232 and distal raised portion233. In this embodiment, distal raised portion 233 has a chamferedsurface so that the collar (not shown) may be easily installed overneedle cover 237 and into recess 234 by sliding the collar over theneedle shield, forcibly past the chamfered distal raised portion 233into recess 234.

FIG. 12 illustrates another alternative needle shield assembly of thepresent invention. This alternative needle shield assembly functionssimilarly to the needle shield assembly of FIGS. 1-8. Alternative needleshield assembly 300, like the needle shield assembly of FIGS. 1-8,includes a needle cannula 321, a hub 328 which includes a base member330, a needle cover 337 and collar 341 rotationally connected to the hubso that the collar can be rotated around the hub. An elongate needleshield 345 is pivotably connected to collar 341 through hinge 344. It iswithin the purview of present embodiment that the base member can be aseparate element attached to the hub using methods described hereinaboveor integrally formed as part of the hub. Rather than having a collarreceiving recess the hub, the present embodiment has an annular flange335. The rotational connection between collar 341 and hub 328 isaffected by engagement of annular flange 335 with annular recess 336inside collar 341.

One of the important features of the present invention is that theneedle shield and collar can be assembled to the hub after the needlecover has been installed, thereby eliminating any potential for damagingthe sharp needle tip during installation of the collar and needle shieldassembly. One way to manufacture the needle shield assembly of thepresent invention is to attach base member 330 to hub 328 using one ofthe many manufacturing processes described hereinabove. The needlecannula is then assembled to the hub using a variety of known methodsfor securing the proximal end of the needle cannula to the distal end ofthe hub with epoxy adhesive being preferred. The needle assemblycomprising the hub which includes the base member, integrally formed orseparately attached, and the needle cannula is then assembled to theremovable needle cover. At this point in the process, there exists acovered needle assembly wherein the needle cannula is protected fromdamage and its cleanliness is maintained by the needle cover. The needleassembly may be sterilized before further assembly into a finishedproduct, or the collar may be joined to the needle hub by advancing thecollar over the distal end of the needle cover, proximally until annularflange 335 contacts chamfered surface 342 on the collar. The chamferedsurface is provided to allow the annular flange to spread the collarslightly so that annular flange 335 can snap into annular recess 336 inthe collar. The needle shield may now be pivoted to its intermediateposition described hereinabove, and packaged and sterilized or attachedto a hypodermic syringe and packaged and sterilized. Sterilization maybe accomplished by gas sterilization such as ETO or radiationsterilization. When using gas sterilization the package can be made ofone hundred percent breathable material or at least have one surface ofbreathable material such as a blister package with a peelable,breathable top. The breathable surface is necessary to carry out the gassterilization process. In radiation sterilization such breathablecomponents can be used but are not necessary. Preferably, a quantity ofpackaged needle shield assemblies or packaged needle shield assembliesattached to devices such as a syringe are placed in a corrugated shipperand sealed before the sterilization process.

It should be noted that throughout the specification the collar has beendescribed as having an aperture of 360° in duration. It is within thepurview of the present invention to have an aperture less than 360° andgreater than 180° in duration which will be sufficient for the collar tobe rotationally attached to a hub. FIG. 13 illustrates an alternativecollar and needle shield assembly 400 which functions substantiallyidentically to the embodiment of FIGS. 1-8. However, in this embodiment,collar 441 is semi-circular shaped having an aperture 442 of less than360° and greater than 180° in duration. Collar 441 can be assembledaxially over the needle cover and onto the needle hub using methodsdescribed hereinabove. Also, it may be assembled by moving said collarhorizontally toward said hub and snapping the aperture over theappropriate structure on the needle hub. In either case the alternativeneedle shield and collar 400 maintains the important advantage of thepresent invention that collar and needle shield may be assembled to theneedle hub after the needle cannula and needle cover have beeninstalled.

It can be seen that the present invention provides a self-containedneedle shield assembly and a method of making wherein the needle shieldcan be positioned in the needle shielding position using a one-handedprocedure and the needle shield automatically locks in the needleshielding position so that the needle is unable to be reused. The needleshield assembly of the present invention also provides structure toprotect the cleanliness of the needle until the needle is first used.The present invention also provides a self-contained needle shieldassembly which allows the needle to be used twice, once for withdrawingmedication into a syringe and then for injecting medication into apatient, while providing means for preventing the permanent locking ofthe needle shield until the final use by preventing the needle shieldfrom being pivoted into the closed position while the needle cover isinstalled. The present invention also provides the advantage that theneedle shield can be rotated with respect to the needle hub so that theneedle shield can be oriented with respect to a needle cannula which hasa sharpened beveled tip having a beveled surface. The advantage beingthat the needle shield can be rotated to the same side as the needleassembly as the bevel surface faces, making it easier to pierce apatient's vein without experiencing interference from the needle shield.Finally, the present invention provides the advantage of not havingintermediate elements separating the needle hub from the fluid handlingdevice, such as a syringe, which can waste medication by lengthening thefluid path, and making the entire assembly longer and possibly moredifficult to use.

What is claimed is:
 1. A needle shield assembly having a single-usecannula lock comprising:a needle cannula having a proximal end, a distalend and a lumen therethrough defining a longitudinal axis; a hub havinga proximal end for connecting to a fluid transfer device and a distalend connected to said proximal end of said needle cannula; a collarrotatably connected to said hub so that said collar can be rotatedaround said hub; an elongate rigid needle cover removably engaging saidhub and covering said needle cannula; an elongate needle shield having adistal end and a proximal end hingedly connected to said collar, saidneedle shield including two side walls defining a longitudinal openingand a back wall between said side walls defining a recess having aninterior surface, said needle shield capable of pivoting from an openposition wherein said needle cannula is exposed, to a closed needleprotecting position wherein said needle cannula is within saidlongitudinal opening of said needle shield; means for preventing saidneedle shield from being pivoted into said closed position while saidneedle cover is engaging said hub; means for locking said needle shieldin said closed needle protecting position when said needle shield ispivoted into said closed position, said means for locking includingneedle cannula locking means for trapping said needle cannula in saidlongitudinal opening of said needle shield.
 2. The needle shieldassembly of claim 1 wherein said needle cannula locking means includesan arm projecting from said interior surface of said needle shield, saidarm having a transverse portion at its free end including a ledgepositioned so that when said needle shield is pivoted to said closedposition, said needle cannula snaps past said transverse portion and istrapped in said needle shield by said ledge.
 3. The needle shieldassembly of claim 2 wherein said arm projects outwardly from said backwall into said recess.
 4. The needle shield assembly of claim 2 whereinsaid needle cannula locking means includes an inclined wall having asurface for urging said needle cannula toward the center of saidlongitudinal opening as said needle shield is being rotated into saidclosed position.
 5. The needle shield assembly of claim 4 furtherincluding a second inclined wall opposed from said inclined wallpositioned so that when said needle shield is in said closed positionsaid needle cannula is between said inclined wall and said secondinclined wall.
 6. The needle shield assembly of claim 1 wherein saidmeans for preventing includes at least a portion of said side wallsbeing formed so that said longitudinal opening is smaller than saidneedle cover so that said needle cover must be removed before saidneedle shield can be pivoted to said closed position.
 7. The needleshield assembly of claim 1 further including means for releasablyretaining said needle shield in said open position.
 8. The needle shieldassembly of claim 7 wherein said means for releasably retaining saidneedle shield in said open position includes a projection on said collarengages said needle shield when said needle shield is pivoted to saidopen position.
 9. The needle shield assembly of claim 7 wherein thelongitudinal opening of the needle shield is positioned between about90° to 180° from said longitudinal axis of said needle cannula when saidneedle shield is in said open position.
 10. The needle shield assemblyof claim 1 further including means for releasably retaining said needleshield in an intermediate position between said open position and saidclosed position.
 11. The needle shield assembly of claim 10 wherein saidmeans for releasably retaining said needle shield in said intermediateposition includes a protrusion on said needle shield which engages saidneedle cover.
 12. The needle shield assembly of claim 1 wherein saiddistal end of said needle cannula includes a sharp tip.
 13. The needleshield assembly of claim 12 wherein said sharp tip is bevel-shapedhaving a bevel surface.
 14. The needle shield assembly of claim 13wherein said bevel surface faces the same side of said collar as saidneedle shield when said needle shield is in said open position.
 15. Theneedle shield assembly of claim 1 wherein said collar and said needleshield are connected by a living hinge and made of a unitary one-piececonstruction.
 16. The needle shield assembly of claim 1 furtherincluding a syringe barrel having a distal end, a proximal end and acircular side wall therebetween defining a chamber for retaining fluidand a longitudinal axis, said distal end of said syringe barrel beingconnected to said hub so that said lumen in said needle cannula is influid communication with said chamber.
 17. The needle shield assembly ofclaim 1 further including means for applying torque to said hub tofacilitate the installation and removal of said needle shield assemblyand a fluid transfer device.
 18. The needle shield assembly of claim 16wherein said hub and said syringe barrel are made of a unitary one-piececonstruction.
 19. The needle shield assembly of claim 1 wherein saidcollar includes a circularly-shaped aperture of greater than 180° butless than 360° in duration surrounding said hub.
 20. A needle shieldassembly having a single-use cannula lock comprising:a needle cannulahaving a proximal end, a distal end and a lumen therethrough defining alongitudinal axis, said distal end of said needle cannula including asharp tip; a hub having a proximal end for connecting to a fluidtransfer device and a distal end connected to said proximal end of saidneedle cannula; a collar rotatably connected to said hub so that saidcollar can be rotated around said hub; an elongate rigid needle coverreleasably engaging said hub and covering said needle cannula; anelongate needle shield having a distal end and a proximal end hingedlyconnected to said collar, said needle shield including two side wallsdefining a longitudinal opening and a back wall between said side wallsdefining a recess having an interior surface, said needle shield capableof pivoting from an open position wherein said needle cannula isexposed, to a closed needle protecting position wherein said needlecannula is within said longitudinal opening of said needle shield; atleast a portion of said longitudinal opening being smaller than saidneedle cover so that said needle cover must be removed before saidneedle shield can be pivoted to said closed position; said needle shieldincluding an arm projecting from said inside surface of said needleshield, said arm having a transverse portion at its free end including aledge positioned so that when said needle shield is pivoted to saidclosed needle protecting position, said needle cannula snaps past saidtransverse portion and is trapped in said needle shield by said ledge tolock said needle shield in said closed position.